import math
def equation(a,b,c):
	arr = [a,b,c]
	arrLen = len(arr)-1

	
	for num in arr:
		if not isinstance(num,(int,float)):
			raise TypeError('bad operand type')
	pass


#切片
def trim(s):
	if s[0]==' ':
		s[0]=''
	if s[-1]==' ':
		s[-1]=''
	return s
	
print(trim(' syg'))